Wash bottles used in laboratories and the like include a compliant container which is squeezed, whereby liquid in the container which may be volatile or toxic is expelled therefrom through a syphon tube extending within the container and into the liquid. The syphon tube communicates with a dispensing nozzle. The dispensing nozzle is preferably but not necessarily integral with a cap for the container.
Prior to the present invention, bottles of the type described have suffered from a syphoning effect. That is to say, whenever there is a pressure differential between the inside and the outside of the bottle, the liquid in the container flows through the syphon tube and nozzle so as to drip or squirt out of the bottle, tending to equilibrate the inside and outside pressures. This can occur if the bottle is on a storage shelf or is otherwise not being used, and the aforementioned pressure differential occurs as by opening or closing a door in an atmospherically controlled room in which the bottle is kept, or when an air conditioning system for the room is turned on or off, as the case may be. When the contents of the bottle are volatile or toxic as aforenoted, a hazard, or at best a clean up problem, can occur.
The present invention avoids the noted syphoning effect, thereby achieving pressure equilibrium without expulsion of the contents of the bottle.
The applicants herein are aware of the following patents which generally relate to the field of the present invention: U.S. Pat. No. 4,600,130 which issued on Jul. 15, 1986 to Libit; U.S. Pat. No. 4,420,101 which issued on Dec. 13, 1983 to O'Neill; U.S. Pat. No. 4,133,457 which issued on Jan. 9, 1979 to Klassen; U.S. Pat. No. 3,118,573 which issued on Jan. 21, 1964 to Johnson; U.S. Pat. No. 4,102,476 which issued on Jul. 25, 1978 to Loeffler; and U.S. Pat. No. 4,057,177 which issued on Nov. 8, 1977 to Laauwe.
The patent to Libit relates to a squeeze type container and cap, wherein the container has an integral section forming a tube extending from within the container to the container neck opening. The cap has a stopper portion closing a filling part of the container neck opening and has a dispensing orifice in communication with the tube portion of the container. The invention appears to relate to increasing the internal pressure within the container.
The patent to O'Neill relates to a self-venting dispensing closure for a squeeze bottle and includes a cap containing a fluid opening. A flexible disc on the cap contains a fluid bore which defines with the opening a single fluid passageway. The cap includes an annular wall defining a valve seat upstream of the fluid opening in the direction of fluid flow through the passageway. The disc has an annular valve thereon in engagement with the valve seat in a closed position of the passageway, and the valve is shiftable along the annular wall to positions respectively upstream and downstream of the valve seat in response to pressures below and above atmospheric pressures within the bottle. In these shifted positions, the valve opens respectively into bottle venting and dispensing positions.
The patent to Klassen relates to a squeeze bottle with a sealing arrangement which prevents spillage of the contents of the bottle due to accidental dropping or tipping over. To this end the bottle has a resilient septum spanning a dispenser outlet and sealed in place by a cap. The septum has a slit which defines a flexible valve flap integrally joined along a hinged lined area to the septum for outward deflection of the flap by internal liquid pressure when the dispenser is squeezed. The septum is also formed with at least one hole, preferably on or near the vicinity of the hinge line area to increase flexibility of the flap, and to serve as a vent to greatly accelerate relaxation and normalization of the squeeze bottle wall.
The patent to Johnson relates to a squeeze bottle and provides a fluid seal for safely retaining the fluid and which functions to release the fluid upon squeezing of the bottle. The seal appears to be in the form of a rupturable diaphragm.
The patent to Loeffler relates to a squeeze bottle with an air check valve on its cover. The bottle dispenser has an air return flow path therethrough and a valve therein opening the air return flow path when the pressure on the outside of the container is greater than the pressure on the inside of the container. Actually, the object of the invention is to provide a squeeze bottle dispenser in which the flow passages for both the liquid to be dispensed and the air compressed for atomizing said liquid will automatically close by a single valve means at the conclusion of the operation of the device.
The patent to Laauwe relates to a squeeze bottle with a valve comprising two parts cooperatively forming a chamber into which a viscous product can be squeezed by squeezing the bottle to elastically separate the parts which together form a sleeve valve opened by the separation of the parts, and which recloses when the bottle squeeze pressure is released so the parts return. One of the parts forms a check valve permitting entrance of air into the bottle.
It will be apparent from the following description of the present invention that none of the aforementioned patents teach or suggest the particular structural relationship herein disclosed.